Illuminated gage.



No. 641,302. Patented Jan. l6, I900. F. LANE.

ILLUMINATED GAGE.

(Application filed Mar. 3, 1898.)

(No Model.)

' NrTE FREDERICK LANE, OF BROOKLINE, MASSACHUSETTS, ASSIGNOR TO THECROSBY STEAM GAGE AND VALVE COMPANY, OF BOSTON, MASSA- CHUSETTS.

ILLUMINATED GAGE.

SPECIFICATION forming part of Letters Patent No. 641,302, dated January16, 1900.

Application filed March 3,1898.

T0 ctZZ whom it may concern.-

Be it known that I, FREDERICK LANE, a citizen of the United States,residing at Brookline, in the county of Norfolk and State ofMassachusetts,have invented certain new and useful Improvements inIlluminated Gages; and I do hereby declare the following to be a full,clear, and exact description of the invention, such as will enableothers skilled in the art to which it appertains to make and use thesame.

This invention relates to a new and useful. improvementin an illuminatedgage-that is, a gage of. any kind wherein it is desirable that theregistration of its operation may be read at night on a dial which isilluminated by artificial means.

In the drawings,Figure 1 represents a transverse diametric section ofthe device; Fig.- 2, a rear View with parts broken away; Fig. 3,- apartial detail section of a modification.

In the drawings the letter A represents a gage-case provided in frontwith a chamber B for containing the usual gage mechanism and at the rearthe receptacle C for con taining the illuminator, the chamber B havingan opening 5 and the receptacle C an opening 0, the two being placed sothat the openings come together, as shown in Fig. 1. The chamber B andreceptacle C are secured together at their circumferential flanges b ando by suitable bolts, an annulus D or flat strip of asbestos beinginterposed between the meeting edges. Surrounding the opening 6 there isa recess or seat o in which rests the edge of a sheet of mica E. Thissheet of mica is held in place in the recess 5 by a ring 03. Within, atthe top and bottom of receptacle C, are placed reflectors F G, flat orcurved, the upper one, F, having an openingf, down through whichprotrudes the electric lamp H or other source of light. In the bottomand top of the receptacle C are made air-holes 0 Instead of the singletransparent division dividing the chamber and receptacle there may betwo or more such partitions making this division, as seen in Fig. 3. Insuch construction there is a sheet of mica placed in each of the meetingfaces similarly arranged,

Serial No. 672,368. (No model.)

as shown in Fig. 1. In this construction there is an air-space I betweenthe chamber and the receptacle and openings'i at bottom and top, onlythe top openings being shown, the bottom ones being a duplicateconstruction.

Illuminated gages are not new per se; but, so far as I am aware, suchgages have no interposing partition between the artificial light and thetransparent dial. Also in gages where the Bourdon tube-spring is used itis necessary that it should be kept cool or in low temperature, so thatit shall not expand, and thus incorrectly move in its use whatever maybe the fluid acting within 'it. To prevent the transmission of any heatfrom the illuminator to the operative parts of the gage, theinterposition of a partition of some non-heatconducting substancesufficiently translucent to permit the passage of the rays of light, sothat the face of the dial may be properly inspected, is desirable. Nowmica, which is a tough and transparent substance, accomplishes what isdesired in this regard. Also asbestos interposed between the flangesprevents the transmission of heat from one case to the other. Whileglass would subserve the same purpose as mica, still it is not quite so.

advantageous, as it is liable to be broken by the heat. Again, a doublepartition will better secure the results than a single partition.

Having described the invention, what I claim is- As a new article ofmanufacture, a gage having the chamber, B, for the gage mechanism andthe receptacle, C, for an illuminator secured together with an openingbetween them; a ring of asbestos, D, between the meeting edges of thetwo; a sheet of mica, closing the opening between the chamber andreceptacle; the reflectors, E and F, at top and bottom of thereceptacle, C, and a source of light between the two reflectors, as setforth.

In testimony whereof I affix my signature in presence of two witnesses.

FREDERICK LANE.

Witnesses:

J. H. MILLETT, ARTHUR L. BOWKER.

